Electric rivet-heater.



W. S. JOHNSON & J. W. SHEFFER.

ELECTRIC RIVET HEATER.

APPLICATION FILED my. 25. 1916- Patented Dec. 19,1916.

a SHEETS-SHEET 1.

In (261160715 PhiZZiam 5T d oil/msom W. 3.,J0HNSON & J. W. SHEFFER.

ELECTRIC RIVET HEATER.

APPLICATION FILED FEB. 25. I916.

Patented Dec. 19, 1916.

3 SHEETS-SHEET 2.

In vendors William 18 lfokzwon 70km WAS/@1966? 5 g?! 14.

W. S. JOHNSON-& J. W. SHEFFER.

ELECTRIC RIVET HEATER.

APPLICATION FILED FEB. 25, I916.

Iatexited Dec. 19,1910.

3 SHEETS-SHEET 3- Big: 12. Fig. 1.5:

Big. 70.

6 nm r 5 00.

O s kw Big. 11.

TED STATES PATENT OFFICE.

WILLIAM S. JOHNSON AND JOHN W. SHEFFEB, OF BEBWICK, PENNSYLVANIA, ASSIGN- OBS TO AMERICAN CAR AND FOUNDRY COMPANY, OF ST. LOUIS, MISSOURI, A COB- PORATION OF NEW JERSEY.

ELECTRIC RIVET-HEATEB.

Application filed February 25, 1916. Serial No. 80,421.

To all whom it may concern:

Be it known that we, WILLIAM S. JOHN- that the invention is not limited to the exact details of construction shown and described, as it is obvious that various modifications thereof will occur to persons skilled in the art.

In said drawings: Figure l is a front elevation of our improved electric rivet heater.

Fig. 2 is a side elevation thereof. Fig. 3 is a plan view of the rivet heater, one of the upper core. binders being removed and a portion of the secondary winding being broken away. Fi 4 is a development of the secondary coil. l ig. 5 is a fragmentary-elevational view of one corner of one of the primary coils showing the method of assembling said coil. Flg. 6 is an elevational view of one of the primary winding separators. Fig. 7 is a detail view of one of the It is proposed that the secondary coil shall constitute a self-contained secondary circuit. The secondary coil-contained secondary'circuit is normally open and is adapted to be closed by the insertion of one or more pieces of work in a branch or branches of itself.

A novel construction is given to the secondary coil whereby any of its branches may act by gravity, or by gravity assisted by other means, to adjust the branch affected to Specification of Letters Patent.

Patented Dec. 19, 1916.

receive work, after which other 'means, under the control of an operator, are adapted to automatically accommodate the work and proper terminals or electrodes of the secondary coil to each other.

Other features, including the regulation of the voltage in the secondary or work circuit to adapt the latter to work of different sizes and also the method of thermally and electrically insulating the device, together with the construction of. the primary coils, are all parts of the present invention as will appear hereinafter.

In the embodiment of the invention illustrate'd in the drawings, a suitable stand is provided upon which is mounted a properly electrically and thermally insulated transformer. The transformer is provided with a secondary coil of peculiar construction which has a single upper terminal or electrode and a plurality of lower terminals or electrodes adapted to cooperate therewith. The lower electrodes are movable in guides and a rivet or other piece of work is adapted to be positioned between any or all of the lower electrodes and the upper electrode whereby it or they may be subjected to heat treatment b the current induced into the secondary coi Each lower electrode may be independently controlled by a spring and treadle-controlled rod as herelnafter set forth.

Referring specifically to the parts, side frames 1 are suitably spaced from each other and each comprises upwardly extending front and rear legs 2 and 3, respectively, a lower tie bar 4 and a top tie bar 5. The latter and the upper part of front leg 2 of each side frame is projected forwardly of the machine to form brackets 6 ada'ptedto support- 4 a box 7 intended to contain a supply of riv-.

ets to be heated.

The lower portions of front legs 2 are connected by a front plate 8, while the rear legs 3 are suitably tied together by a back plate 9. The lower tie bars 4 support and are connected by a fulcrum beam 10. The elements of each side frame are preferably angular in cross section and those of one element .merge with those next adjacent and a continuous outstanding flange bounds the contour of each of said side frames The side frames 1 are alsoconnected by a vertically disposed'guide plate 17 which has a flange portion 11 resting upon the outstanding upon the upper surface of the side edges of transformer 12 and bolts 16 pass through the horizontal flanges of the upper and lower .core hinders 15 and 13, respectively, spacers 14 and the outstanding horizontal flange of upper tie bars 5 of the side frames 1, securely positioning the transformer core- 12. Both upper and lower core binders 15 and 13, respectively, may conveniently be constructed of commercial angle irons, the lower core binder having its horizontallv disposed flange cut away shortly in front of the transformer core 12., its vertical flange extending to and being bent to lie behind guide platelY, bolts 18' and 19 firmly securing the upright portion of guide plate 17 to said lower core binder 13. The guide plate 17 is therefore very rigidly combined with the stand and transformer structureand its function will be referred to shortly Transformer core 12 is of the laminated type and is, by choice, rectangular in form. Threaded upon its forward leg 20 is a pair of primary coils 21 and substantially enveloping the primary coils is a secondary coil 22. The latter is composed of laminated copper sheets 22 which are bent about the primary coils and extend somewhat in advance of the same. The upper terminal edges of the laminated copper sheets 22* are merged with an upper electrode 23 and the lower terminal edges of copper sheets 22 are substantially connected with a series of lower.

electrodes 24. This merging of the secondary coil sheets '22 with electrodes 23 and 24 may readily be accomplished by casting them into said electrodes when the latter are being formed. The lower portions of the secondary laminated sheets 22 are slit as shown at 22 said slit portion and lower electrodes 24 havmg substantially the same width as illustrated in Fig. 4. Upper electrode 23 "has a width equal to the unslit width of the secondary coil 22 which also corresponds to the Width of the lower terminals 24 and the spaces between them.

The vertically disposed flanges of core binders 15 are longer thanfthe horizontally disposed flanges and they extend almost to and are bent to lie behind the rear face of upper electrode 23, insulation sheets 25 being interposed between said upper electrode 23 and each bent forward end of the upper core binders 15.

Bolts 26 and 27 pass through insulating aaeaeae Guide plate 17 is provided with verticallydisposed spaced ribs 28 to which are bolted retaining strips 29 and 29 Guideways are ,thus formed in which the lower electrodes 24, hereinafter called movable electrodes, are adapted to slide vertically.

As best shown in Fig. 3 the front face of the guide plate is indented as at 30 reducing the amount of friction between the movable electrodes 23 and the guideways in which they slide.

Lower electrodes 24 normally are positioned a relatively small distance be-.

neath the stationary electrode 23 and the Y branched portions of the secondary laminated sheets 22 formed by slits 22 are flexible whereby easy movement of any of movable electrodes 24 is permitted.

Attached by bolts or other suitable means to each lower movable electrode 24 is a depending rod 31 which passes downwardly through apertures in a horizontal flange 32 projecting rearw'ardly from front plate 8. Lower ends of rods 31 are flattened and pivotally connected with treadle levers 33, the latter being pivoted to upstanding ears in brackets 34 on the fulcrum beam 10. Said treadle levers 33 each pass through aslot in the front plate 8 and at their outer ends are twisted to form a foot plate.

Surrounding each lower electrode-moving rod 31 is a compression spring 35, the lower end of which is seated upon horizontal flange 32 of front plate 8, the upper end of said spring bearing against a washer 39 held in fixed position with respect to rod 31 by said spring and pin 40. Springs 35, therefore,

exert an upward push upon the rods 31. and

. electrode 23.

Regulation of the force of springs 35 may easily be made either by changing the washer retaining pins 40 from the holes they-occupy in the upper part of rods 31 to others of adjacent series of holes or by changing the pivots connecting the lower ends of. said rods 31 to the treadle levers 33 from the holes they occupy to adjoining holes 42. I I

The tension of the springs 35 having been properly adjusted and it being desired to heat rivets, or other articles, the operator presses a treadle lever 33 downwardly, the rod 31 connected therewith drawing its lower electrode 24 downwardly against the action of the spring 35 surrounding that rod 31. Selecting a rivet from box 7, the operator places it between the lowered electrode 24 and the upper stationary electrode 23 and relieving the pressure upon the treadle lever 33 permits spring 35 to force the lower electrode 24 under consideration upwardly until the rivet is held as shown at A in Figs. 1 and 8. Referring to Fig. 8, if switches 43, 44 and 45 have been closed and the blade of. switch 46 has been thrown into switch socket 47 current will flow from the alternating current generator 48 through conductor 49 to contact 50, by bridge 51 to contact 52, from thence going by conductor 53 to the blade of switch 46, socket 47, and conductor 54 to conductors 55 and 55 to each of the primary coils 21. After passing through all of the primary coils 21 the current emerges by conductors 57 and 57, that passing through conductor 57 going to switch 45 and that passing through conductor 57 going to socket 58 of switch 44, through the then closed switch 44 and by conductor 59'to a junction with conductor 57 and from there to closed switch 45. Progressing from switch 45 the current returns by conductor 60 to the other side of the alternating current generator 48. A current is therefore induced into the secondary winding 22 of the transformer by the energized primary coils 21 and passes through the rivet at A heating the same? It is to be understood that while but one rivet has been shown, in ordinary practice a rivet will be inserted between each lower movable electrode 24 and the single upper stationary electrode; 23 and the current will pass through all of these rivets heating them in unison.

Under usual shop conditions, one rivet will be inserted after the other and the first insertedrivet will become heated and removed first, another rivet being immediately inserted to replace it, so that the full capacity of the heating apparatus will be utilized. During any interval when a rivet is not in place between one of the lower movable electrodes and the upper stationary electrode, the entire current will be diverted to the electrodes then in service and all of the current except for a slight loss will pass through the remaining rivets. A more rapid heating of these remalning rivets will result, compensating for any loss of time due to the replacement of rivets.

It frequently occurs that it is necessary to heat different sized rivets for differently proportioned work and the'heating apparatus is so designed that greater current may be applied to larger pieces of work, rendering the installation of an undue number of heating devices unnecessary. When larger rivets, for instance, are to be heated, switch 46 is thrown from socket 47 to socket 61. Switches 43, 44 and 45 remaining closed, current will flow from generator 48, by conductor 49, to contact 50, through bridge 51 to contact 52 by conductor 53 to the blade of switch 46 and by socket 61 and conductor 62 and conductors 63 and 63 to and through lesser portions of primary coils 21. Return,- ing from primary coils 21 current traverses conductors 57 and 57, the current in conductor 57 going to switch 45 and that in conductor'57 going to socket 58, through the blade of switch 44 and by conductor 59 to conductor 57, thence to the blade of switch 45 and by conductor 60 to the other side of the generator 48. An increased current will therefore be induced into the secondary coil 22 and will pass through all of the larger rivets positioned between the lower movable electrodes 24 and the upper stationary electrode 23, eliminating the necessity for. a longer period of heat application to said larger rivets.

Due consideration has been given to the thermal and electrical insulation of the rivet heating apparatus. That the high temperature necessary to properly heat the rivets may not have a detrimental efi'ectupon the electrical coils, a sheet of thermal insulation 82, such as transit asbestos, is interposed between the rear faces of the stationary electrode 23 and the guide 17 for the movable electrode 23 on the one hand and-the primary windings 21 on the other.

Insulation 82, shown in Fig; 10, is firmly held in place by the bolts 26 which pass through the stationary electrode 23 and the forward bent end portions of the vertical flanges of core binders 15 and also by the bolts 19 which extend through guide plate 17 and the forward bent end portions of lower core binders 13.

Short tubular spacers 84 serve to properly position insulation sheets 82 from the inner faces of the bent ends of the vertical flanges of .the upper and lower core binders 15 and 13, respectively.

A sheet of insulation 64 depicted in Fig. 13 surrounds the same leg of the transformer that is threaded through the primary coils 21, having a central aperture toaccommodate the transformer core 1e and being disposed between the pair of p imary coils 21.

Somewhat similarly shaped sheets of in sulation 65, best shown in Fig. 12 are positioned between the outer ends of primary coils 21 and the transformer legs parallel with said outer ends of said primary coils. Between the rear faces of the primary coils 21 and the adjacent inner face of the sec-- is thoroughly insulatedby a casing of insulation wrapped with insulating tape'69, as is also the rear transformer leg parallel with it.

As seen in Fig. 2, another sheet of insulation 70 lies between the upper. surfaces of primary coils 21 and the under surface of the upper horizontal leg of the secondary coil 22, the contour of sheet 70 being shown in Fig. 9. It will therefore be seen that in addition to being insulated from the transformer core and the secondary winding each primary coil 21 is housed in anopen insulatmg box.

Primary coils 21 are uniquely wound, insulated and ventilated; each of said primary coils is wound to correspond to the over the exposed portions of the innermost layer of the wound wire.

Another separator 71 is placed at the exposed rounded corners of the first layer of wire and the second layer of wiring is wound as before, and again other insulation 74 is applied as before, the building up of each primary coil continuing in this manner until the outside layer of wire has been wound. The ends of separators 71 project beyond the sides of the primary coils and those of each set are tied together by suitable cord or other wrapping means 75.

Where the primary coils 21 are tapped by conductors-63 and 63 no severance of the wire occurs. a The cloth or other covering of the wire is stripped away. and said wire is folded as shown at 7 6 in Fig. 7. A copper tube 77 drilled to receive binding screws 78 and 7 9 has one of its ends slipped over the folded wire portions 76, the binding screws 78 being tightened to clamp the tube and bent wire firmly together. Conductor 63, has a bared endwhich is inserted into the opposite or outerendof tube 77 and is clamped therein by thebinel-ing screws 79.

.If desired the copper tube-77 may be wrapped with insulating tape 80. The separators may be of such dimensions that the wiring in successive layers in the primary coils 21 may be sufficiently spaced to allow currents of air to' pass therethrough and cooland further-insulate the same.

The boxes of insulation, hereinbefore referred to as eachcontaining one of the primary coils, are created by the arrangement of the. front sheet of insulation 82, the rear insulation sheet 66, the central perforated insulation sheet 64 disposed between the primary coils, the side or end perforated insulation'sheets 65 and the top insulation sheet disposed between the upper faces of the primary coils 21 and'the underside 'ofthe upper horizontal leg of the secondary coil and the meeting corners of the sheets being unsecuredpermits of ventilating air currents passing through the boxes and through the peculiarly ventilated primary coils.

We claim: v

1. Tn combination in an electric heating apparatus, a transformer comprising a primary winding and an open secondary coil comprising electrodes and continuous uninterrupted conductors extending therebetween and connected thereto, said coil constituting a complete secondary circuit adapted to be closed by-work, and a source of electrical energy in circuit with said primary winding.

2. In combination in an electric heating apparatus, a transformer comprising a primary Winding and a unitary secondary coil provided with a plurality of mutually connected branches and constituting a coilcontained complete work-circuit, each branch being adapted to receive work, and a-source of electrical energy.

3. In combination in an electric heating apparatus, a transformer provided with asecondary coil comprising a main portion branched Within itself and having terminals and electrodes at the terminals and forming a coil-contained work-circuit, and a source of electrical energy for saidtransformer.

4. In combination inan electric heating apparatus, a transformer secondary coil comprisin laminated and conjoined portions, the former having a main portion and branches and the conjoined portionsform-' ing electrodes, said laminated and conjoined portions constituting a coil-contained workvcircuit adapted to receive a plurality of pieces of work.

means for actuating desired electrodes so that current may flow throu h a single path or plurality of paths at will throughwork, and a source of electrical energy.

7. In combination in an electric heating nected to said single path portion common,-

to the first mentioned electrodes, means for adjusting the electrodes to so hold work that current may flow through the same and one or more of said branches, and a sourc of electrical energy. 7 Y

8. In combination 1n an electric heating apparatus, a supporting structure, a transformer carried thereby and provided with a secondary coil constituting a coil-contained secondary circuit having branches, electrodes for each branch and an opposing electrode therefor connected to an opposite terminal of said coil, means coiiperating with said supporting structure for maintaining said branch and opposing electrodes in workholding positions, devices for separating said electrodes, and a source of electric energy.

9. In combination in an electric heating apparatus, a supporting structure, a transformer mounted thereon and provided with a secondary coil, electrodes at opposing terminals of said coil, clampin members 7 maintaining'said transformer in position,

and forming a support for an electrode-carrying terminal of said coil and for a guide for the electrodes opposing the same, means for relatively moving opposing electrodes toward and from each other, and a source of electrical energy in circuit with said transformer.

10. In combination in an electric heating apparatus, a supporting structure, a transformer mounted thereon and provided with a laminated core and a secondary coil having opposing electrodes, core clamping devices provided with flanges forming supports for one electrode-carrying end of said secondary coil and for a guide, a guide for the electrodes opposing said supported coil end electrode, means for normally maintain-' ing said opposing electrodes in juxtaposed relation and means for separating the same.

11. In combination in an electric heating apparatus, a supporting structure comprising spaced upstanding frames, a member 1 connecting the same and provided with a spring seat portion and a' plurality of other side frame connecting members one being.

an electrode guide member provided with a plurality of guideways, a transformer mounted on said supporting structure and having a secondary coil-carrying opposing stationary and movable electrodes the movable electrodes being slidable in said guideways, means for independently actuating said movable electrodes and springs cooperating with. said means and spring seat to normally maintain said opposing electrodes juxtaposed.

12. In combination in an electric heating apparatus, a supporting structure, a spring seat therein, a transformer mounted on said structure and having a. secondary coil provided with stationary and movable electrodes, levers pivotally mounted on said structure, rods connecting said levers and movable electrodes for independently actuating the latter, spring-devices cooperating with said spring seat and rods for normally maintainin said stationary and movable electrodes 1uxtaposed, and means for-regulating the spring pressure. 13. In combination in an electric heating apparatus, a supporting stand comprising side frames, a front plate and othermembers tying said side frames together including a fulcrum member, a transformer mounted on said stand and having a secondary coilprovided with opposing stationary passing through said primary and secondary coils.

15. In combination in an electric heating apparatus, a transformer comprising primary coils, a normally open secondary coil provided with subdivisions .and opposing electrodes for said subdivided secondary coil and constituting a coil-contained workcircuit and a core having insulated legs one passing through the transformer coils, insulation sheets interposed between said coils and transformer core and means for chang-.

ing the energizable lengths of said'primary coils by a single operation.

16. In combination in an electric heating apparatus, a transformer comprising primary and secondary coils the latter being provided with opposing stationary and movable electrodes and constituting a normally open coil-contained work-circuit and a core having insulated legs one passing through the transformer coils, a guide for said movable electrodes and insulation sheets interposed between said coils and core and the former and said electrodes and guide thermally and electrically insulating the apparatus- 1 17. In combination in an electric heating apparatus, a transformer comprising primary and secondary coils the latter being provided with opposing stationary and movable electrodes and a laminated core having insulated legs one passing through said coils, a guide for said movable electrodes, 'spaced core binders embracing said core and forming supports for said stationary electrode and guide, means clamping said core binders and core together, insulation between said stationary electrode and its supporting core binders and insulation interposed between said coils and core and the former and said electrodes and guide thermally and apparatus, a transformer comprising primary coils and a secondary coilconstituting a work-circuit, said primary coils each comprising insulated wire wound in layers, insulating spacers having seats for said wire.

separating said layers, insulationinterposed.

between said layers of wire and means for retaining said spacers in position.

20. In combination in an electric heating apparatus, a transformer comprising primary coils and a secondary coil constituting a work-circuit, said primary coils each comprehending insulated wire wound in turns a turn having a portion free from insulation the bared wire being bent to project in a rebent manner, a current-conducting connector slipped over said rebent bared wire, a lead securedto said connector and means attach ing said connector to said bared wire. 21. In combination in an electric heating apparatus, a transformer comprising primary coils and a secondary coil constituting a work-circuit, said primary coils each comprehending insulated wire wound in turns a turn having a portion free from insulation the bared wire being bent to project in a re bent manner, an externally insulated current-conducting connector attached to said rebent bared wire and a lead joined to said connector.

22. In combination in an electric heating -apparatus, a transformer comprising primary coils and asecondary coil'having a single terminal and opposing branched flexible terminals, an electrode for each branched terminal and an electrode for said single terminal adapted to cotiperatewith all or any of said branch electrodes, leads and taps from'said primary coils, a primary circuit, 'asource of energy and switches in said circuit adapted to permit said primary coils to Lana-tee be energized at will and the voltage therein regulated by diverting the current from some of said leads to said taps.

i 23. In combination in an electric heating apparatus, a transformer comprising primary coils and a secondary coil having a single terminal and opposing branched flexible terminals, an electrode for each branched terminal and an electrode for said single terminal adapted to cooperate with all or any of said branch electrodes, leads and taps from said primary coils, a primary circuit, a source of energy, means for opening and closing said circuit at will and a single switch adapted to regulate the voltage in said primary coils by diverting the current from some of said leads to said taps.

24. In combination in an electric heating apparatus, a supporting structure, a transformer mounted thereon and provided with a laminated core and a subdivided secondary coil, electrodes at opposing terminals of said coil, clamping means bindingsaid laminated core together and securing said transformer to said structure, means for supporting said secondary coil from said clamping means, a guide for the opposing electrodes, means for relatively moving opposing electrodes toward each other, and a source of electrical energy in circuit with said transformer.

25. In combination in an electric heating apparatus, a supporting structure comprising spaced upstanding members and other members rigidly connecting the latter, an electrode guide provided with a plurality of guideways, a transformer mounted on said supporting structure and having a, second;

ary coil provided with separated currentpath portions, electrodes at opposing terminals of said coil and slidable in said guideways, means for maintaining opposing elec-.

trodes juxtaposed, and means for selectivel separating opposing electrodes. 7

26. In combination .in an electric heating apparatus, a supporting stand comprising side frames or their equivalents and members tyingsaid side frames together, including a fulcrum member, a transformer mounted on said stand and having a secondary coil provided with opposing'stationar'y and movable electrodes, guiding means for the latter, treadle levers pivotally mounted on said fulcrum member and adapted to be operated to separate opposing electrodes, means connecting said treadle levers and, electrodes, and means afi'ecting said connecting means to cause the latter to normally force said movable electrodes toward said stationary.

electrodes. 7

In witness whereof we have hereunto set ourv hands.

WILLIAM S. JOHNSUN. JOHN W. SHEEFER. 

